Have you ever wondered why the stereotypical Anglo-Saxon style old English phrase replaces the word the with the word ye? OK, I admit that I never really wondered either, but it's one of those little tidbits of information that, once you know it, makes you feel like a better English speaker. It turns out that what we've all been pronouncing as /ji/ (rhymes with tree) is actually not originally a y, but instead the Anglo-Saxon letter thorn, written as a capitol Þ and lower case as þ, and pronounced as a dental fricative—a th sound.
Þ capitol letter thorn—UTF-8: 00DE
þlower case letter thorn—UTF-8: 00FE
According to Wikipedia, thorn (or þorn) once originally accounted for both voiced th sound, as in the, and the unvoiced, as in think, but was eventually replaced with the modern th combination—and example of a digraph—and by the letter Y in a few stock mems like ye olde. The letter thorn, þ, is still used in modern Icelandic to represent the unvoiced dental fricative, and even appears on the standard Icelandic keyboard layout.
Incedently, Icelandic also includes the letter eth, capitol Ð and lower case ð, representing a voiced dental fricative. Eth also derives from old (Anglo-Saxon) English, and was once used interchangeably with thorn.
Ð capitol letter eth—UTF-8: 00D0
ðlower case letter eth—UTF-8: 00F0
There now, don't you feel better? Incendentally, if you're now concrned that you don't know where thorn and eth appear in the alphabet, fear not, Michael Everson and Baldur Sigurdhsson can help you out.